Deprecation of SOAP and access_token in Query Parameters

As part of Adobe’s platform-wide modernization strategy, Marketo will officially deprecate support for its SOAP API on October 31, 2025.

While SOAP has served its purpose over the years—especially in legacy environments—REST has long since become the preferred API standard across the industry. It’s faster, easier to work with, and supported by modern tools and frameworks that enable more scalable and secure integrations.

What's Changing?

1. SOAP API Deprecation

All functionality supported by the SOAP API will no longer be accessible after October 31, 2025. If you are using SOAP-based calls—for example, for lead management, program operations, or custom object syncing—it’s essential to begin transitioning to the REST API immediately.

2. access_token Query Parameter Deprecation

Marketo is also deprecating the use of the access_token query parameter in REST API calls. This method of authentication will be discontinued after October 31, 2025, and all integrations must use the Authorization header instead.

Deprecated Format (will no longer work):
GET /rest/v1/leads.json?access_token=XYZ123

Updated Format (required going forward):

GET /rest/v1/leads.json Authorization: Bearer XYZ123

Using the Authorization header is a more secure and industry-standard approach, helping to avoid exposure of sensitive tokens in URLs and logs.

Identifying SOAP Dependencies

If you're unsure whether your applications use the SOAP interface, you can check for:

• References to .wsdl files or webService endpoints in your codebase

• Integration libraries such as Apache Axis, .NET Web Services, or JAX-WS

• Legacy middleware or ETL tools that rely on SOAP bindings

Begin by reviewing internal documentation and auditing your code repositories. Identifying and documenting SOAP dependencies is a critical first step.

The REST API isn’t just a replacement for SOAP—it’s an upgrade in every meaningful way. Key advantages include:

• Modern authentication with OAuth 2.0

• Simplified request structure using JSON

• Improved error reporting and logging

• Compatibility with popular development tools, including Postman, Swagger/OpenAPI, Python, JavaScript, and more

• Better performance for both batch and real-time operations

Example Migration:

• SOAP syncLead() → REST POST /rest/v1/leads.json

Adobe’s REST API is designed for high-performance marketing operations and is continuously updated with new features, which are not available through SOAP.

Planning Your Migration

Adobe provides a dedicated migration toolkit to support customers and partners in this transition. The toolkit includes:

• A comprehensive mapping guide for translating SOAP operations to REST equivalents

• Sample scripts and code templates

• OAuth 2.0 implementation resources

• Best practices for token handling, error management, and rate limiting

Recommended Next Steps

1. Audit your current integrations to locate SOAP usage and access_token query parameters.

2. Refactor all REST API authentication calls to use the Authorization header.

3. Replace SOAP operations with equivalent REST endpoints.

4. Test updated integrations thoroughly in development or sandbox environments.

Now is the time to evaluate your technical stack and plan your migration roadmap!

Happy Marketoíng! 💜